class AError(Exception):
    def __init__(self, ErrorInfo):
        super().__init__(self)
        self.ErrorInfo = ErrorInfo

    def __str__(self):
        return self.ErrorInfo


while (1):
    try:
        b = int(input('请输入一个整数:'))
        if b < 0:
            a = -b
        else:
            a = b
        break
    except ValueError:
        print('输入的不是整数，', end='')
a = str(a)
l = len(a)
count = 1
for i in range(l // 2):
    if a[i] == a[-1 - i]:
        count += count

try:
    if count != 2*(len(a)//2):
        raise AError(f'{b}不是对称数')
    else:
        print(f'{b}是对称数')
except AError as e:
    print(e)
